Quote:
Originally posted by fr33s3x
by the graph we see that
after 20 sec, the train will stop, and it doesnt matter if you add an extra 10, the distance wont change.
v0=40m/s
a=-2m/s^2
t=20s
----------
v=?
x=?
----------
v=v0-at (- because the acceleration is negetive)
v=40-2*20
v=40-40
v=0 - the speed after 20 sec
--------------------------------------
x=x0+v0t-at^2/2
x=40*20-2*20^2/2
x=800-400
x=400
-------------------------------------
the train will travelled 400meter within 20 secs, thats why the train travelled the same distance with 30 sec..
hope i helped.
|
well done! and thanx for proving my point
